This invention relates to push-in electrical connectors of the type wherein the stripped ends of electrical wires are pushed into the connector for the purpose of making electrical and mechanical connection between the wires.
Prior art push-in wire connectors include a housing with a one-piece conductive clip disposed in the housing. The housing insulates the electrical connection made by the clip between the wires. The clip also provides a force against the conductors to retain them in the housing and sustain an electrical connection between the wires. In this way, the conductive clips in prior art wire connectors must provide the dual functions of mechanically retaining the wires within the housing and forming an electrically conductive path between two or more wires.
In order to adequately provide both these functions, prior art conductive clips teach a construction having a first, flat base portion, a second upright portion which has openings positioned adjacent the openings in the housing, and a third spring portion which folds back onto the first portion to define a cantilevered spring. The electrical conductors extend through the openings in the second portion when the electrical conductors are inserted into the housing. Once the electrical conductors extend through the openings, they are positioned between the base and spring portions so as to provide a clamping force to the electrical conductors and retain the conductors within the push-in wire connector. U.S. Pat. No. 4,824,395 shows an example of this construction.
The one-piece construction of prior art conductive clips requires that they be made of materials which provide elasticity and conductivity. Some prior art conductive clips are made of bi-metal constructions with a layer of copper alloy next to a layer of steel. Other prior art conductive clips are made of copper alloys, phosphor bronze or spring temper brass to provide the springlike and conductive characteristics. However, stainless steel could not be used in prior art wire connectors because it does not provide adequate electrical conductivity between the electrical conductors. Thus, it was assumed that stainless steel and other materials with poor conductive properties were undesirable materials from which to make the spring clip because the spring clip had to provide good electrical conductivity.
Other prior art push-in connectors have a spring that is separate from a conductive plate. While this alleviates the materials problem noted above, the prior art constructions of which the present inventor is aware require that the spring and conductive plate be combined, connected or otherwise attached to one another in a sub-assembly outside of the connector housing prior to placement of the sub-assembly in the housing. This complicates the machinery needed to manufacture the connector, leading to higher costs.
The present invention overcomes these aspects of the prior art by providing a pressure spring which can be easily manufactured and that is not required to provide electrical conductivity between the electrical connectors which are placed within the housing. Neither does the spring have to be pre-assembled with any other components prior to final assembly of the connector.
The present invention relates to push-in electrical connectors having a housing including a case and a cap which together define an enclosure. A plurality of front ports are formed in the cap to provide access to the enclosure. Each port receives an end of an electrical conductor such as an electrical wire which has been stripped of its insulation. A rear block in the case defines a plurality of tapered receptacles each one of which is located spaced from and aligned with one of the entry ports. The receptacles receive and retain the free end of a conductor inserted into the connector.
Fixed within the housing and between the ports and receptacles are a pressure spring clip and a busbar. The pressure spring has a base plate from which extend a plurality of legs, one for each port and receptacle pair. The legs flexibly urge the electrical conductors inserted into the connector into electrical engagement with the busbar. The pressure spring""s base plate and the busbar are each supported partially by the case and partially by the cap. The busbar has an angled rear edge that assures two points of contact between the busbar and the conductors inserted in the connector.
The present invention provides a connector construction which is simple to make and assemble and cheaper to manufacture. The connector does not depend upon the pressure spring to provide an electrical path between the conductors. Neither is the pressure spring called upon to align the conductors as that task is accomplished by the aligned pairs of ports and receptacles. Instead, all the pressure spring has to do is bias the conductors into engagement with the electrically conductive busbar. In this way, the material of the pressure spring is not limited to an electrically conductive metal but rather can be made of any material which provides sufficient biasing force to the conductors so as to maintain an electrical connection with the busbar. Further, the pressure spring and busbar need not be connected to one another, nor are they in engagement with one another. This reduces the cost of the connector and reduces the steps required to manufacture the connector.